pic wont load, so am gonna give ya what i know, if its fluttering back and forth constantly then its the gauge. if you dont have seperate guges from one to the ohter then you have to replace the entire cluster

Dash gauge. Tough to tell on the video.... is it twitching real fast while it reads like that? If it's just the bouncing up and down it may very well be the sending unit.

As much as I hate being one of those people... do a search on the forum and you will find oodles of posts regarding the messed up fuel gauge. Depending on what year your vehicle is.. (it looks to be around.. '99?) you can bring your vehicle into GM for a recall. I think it's 03-06 for the recalls.

But welcome to the world of bad GM clusters if you got a twitchin' gauge!

I have the exact same problem. When I put it in neutral the gauge goes all over the place, the needle only moves between beyond full and half a tank the for the entire tank of gas (found that out the hard way) and it flutters. Basically I have all the problems mentioned in every post. :no: